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* [PATCH] drivers: staging: wilc1000/host_interface.c Fix sparse warning: right shift by bigger than source value
@ 2017-06-25 14:40 Guillermo O. Freschi
  2017-06-26 10:27 ` kbuild test robot
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Guillermo O. Freschi @ 2017-06-25 14:40 UTC (permalink / raw)
  To: Aditya Shankar, Ganesh Krishna, linux-wireless; +Cc: Guillermo O. Freschi

Shifting by equal to or bigger than the width of a type results in
undefined behavior. By using a wide enough temporary variable the issue
can be avoided.

Signed-off-by: Guillermo O. Freschi <kedrot@gmail.com>
---
 drivers/staging/wilc1000/host_interface.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/wilc1000/host_interface.c b/drivers/staging/wilc1000/host_interface.c
index f7c22d7b28d1..ed614698c22c 100644
--- a/drivers/staging/wilc1000/host_interface.c
+++ b/drivers/staging/wilc1000/host_interface.c
@@ -2416,10 +2416,12 @@ static void Handle_SetMulticastFilter(struct wilc_vif *vif,
 		goto ERRORHANDLER;
 
 	pu8CurrByte = wid.val;
-	*pu8CurrByte++ = (strHostIfSetMulti->enabled & 0xFF);
-	*pu8CurrByte++ = ((strHostIfSetMulti->enabled >> 8) & 0xFF);
-	*pu8CurrByte++ = ((strHostIfSetMulti->enabled >> 16) & 0xFF);
-	*pu8CurrByte++ = ((strHostIfSetMulti->enabled >> 24) & 0xFF);
+
+	u32 enabled = strHostIfSetMulti->enabled;
+	*pu8CurrByte++ = (enabled & 0xFF);
+	*pu8CurrByte++ = ((enabled >> 8) & 0xFF);
+	*pu8CurrByte++ = ((enabled >> 16) & 0xFF);
+	*pu8CurrByte++ = ((enabled >> 24) & 0xFF);
 
 	*pu8CurrByte++ = (strHostIfSetMulti->cnt & 0xFF);
 	*pu8CurrByte++ = ((strHostIfSetMulti->cnt >> 8) & 0xFF);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] drivers: staging: wilc1000/host_interface.c Fix sparse warning: right shift by bigger than source value
  2017-06-25 14:40 [PATCH] drivers: staging: wilc1000/host_interface.c Fix sparse warning: right shift by bigger than source value Guillermo O. Freschi
@ 2017-06-26 10:27 ` kbuild test robot
  2017-06-26 11:29 ` [PATCH v2] " Guillermo O. Freschi
  2017-06-26 11:47 ` Guillermo O. Freschi
  2 siblings, 0 replies; 4+ messages in thread
From: kbuild test robot @ 2017-06-26 10:27 UTC (permalink / raw)
  To: Guillermo O. Freschi
  Cc: kbuild-all, Aditya Shankar, Ganesh Krishna, linux-wireless,
	Guillermo O. Freschi

[-- Attachment #1: Type: text/plain, Size: 2134 bytes --]

Hi Guillermo,

[auto build test WARNING on staging/staging-testing]
[also build test WARNING on next-20170626]
[cannot apply to v4.12-rc7]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Guillermo-O-Freschi/drivers-staging-wilc1000-host_interface-c-Fix-sparse-warning-right-shift-by-bigger-than-source-value/20170626-173132
config: x86_64-randconfig-x007-201726 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   drivers/staging/wilc1000/host_interface.c: In function 'Handle_SetMulticastFilter':
>> drivers/staging/wilc1000/host_interface.c:2420:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
     u32 enabled = strHostIfSetMulti->enabled;
     ^~~

vim +2420 drivers/staging/wilc1000/host_interface.c

  2404	static void Handle_SetMulticastFilter(struct wilc_vif *vif,
  2405					      struct set_multicast *strHostIfSetMulti)
  2406	{
  2407		s32 result = 0;
  2408		struct wid wid;
  2409		u8 *pu8CurrByte;
  2410	
  2411		wid.id = (u16)WID_SETUP_MULTICAST_FILTER;
  2412		wid.type = WID_BIN;
  2413		wid.size = sizeof(struct set_multicast) + ((strHostIfSetMulti->cnt) * ETH_ALEN);
  2414		wid.val = kmalloc(wid.size, GFP_KERNEL);
  2415		if (!wid.val)
  2416			goto ERRORHANDLER;
  2417	
  2418		pu8CurrByte = wid.val;
  2419	
> 2420		u32 enabled = strHostIfSetMulti->enabled;
  2421		*pu8CurrByte++ = (enabled & 0xFF);
  2422		*pu8CurrByte++ = ((enabled >> 8) & 0xFF);
  2423		*pu8CurrByte++ = ((enabled >> 16) & 0xFF);
  2424		*pu8CurrByte++ = ((enabled >> 24) & 0xFF);
  2425	
  2426		*pu8CurrByte++ = (strHostIfSetMulti->cnt & 0xFF);
  2427		*pu8CurrByte++ = ((strHostIfSetMulti->cnt >> 8) & 0xFF);
  2428		*pu8CurrByte++ = ((strHostIfSetMulti->cnt >> 16) & 0xFF);

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 28132 bytes --]

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v2] drivers: staging: wilc1000/host_interface.c Fix sparse warning: right shift by bigger than source value
  2017-06-25 14:40 [PATCH] drivers: staging: wilc1000/host_interface.c Fix sparse warning: right shift by bigger than source value Guillermo O. Freschi
  2017-06-26 10:27 ` kbuild test robot
@ 2017-06-26 11:29 ` Guillermo O. Freschi
  2017-06-26 11:47 ` Guillermo O. Freschi
  2 siblings, 0 replies; 4+ messages in thread
From: Guillermo O. Freschi @ 2017-06-26 11:29 UTC (permalink / raw)
  To: Aditya Shankar, Ganesh Krishna, linux-wireless; +Cc: Guillermo O. Freschi

Shifting by equal to or bigger than the width of a type results in
undefined behavior. By using a wide enough temporary variable the issue
can be avoided.

Signed-off-by: Guillermo O. Freschi <kedrot@gmail.com>
---
 drivers/staging/wilc1000/host_interface.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/wilc1000/host_interface.c b/drivers/staging/wilc1000/host_interface.c
index f7c22d7b28d1..ed614698c22c 100644
--- a/drivers/staging/wilc1000/host_interface.c
+++ b/drivers/staging/wilc1000/host_interface.c
@@ -2416,10 +2416,12 @@ static void Handle_SetMulticastFilter(struct wilc_vif *vif,
 		goto ERRORHANDLER;
 
 	pu8CurrByte = wid.val;
-	*pu8CurrByte++ = (strHostIfSetMulti->enabled & 0xFF);
-	*pu8CurrByte++ = ((strHostIfSetMulti->enabled >> 8) & 0xFF);
-	*pu8CurrByte++ = ((strHostIfSetMulti->enabled >> 16) & 0xFF);
-	*pu8CurrByte++ = ((strHostIfSetMulti->enabled >> 24) & 0xFF);
+
+	u32 enabled = strHostIfSetMulti->enabled;
+	*pu8CurrByte++ = (enabled & 0xFF);
+	*pu8CurrByte++ = ((enabled >> 8) & 0xFF);
+	*pu8CurrByte++ = ((enabled >> 16) & 0xFF);
+	*pu8CurrByte++ = ((enabled >> 24) & 0xFF);
 
 	*pu8CurrByte++ = (strHostIfSetMulti->cnt & 0xFF);
 	*pu8CurrByte++ = ((strHostIfSetMulti->cnt >> 8) & 0xFF);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH v2] drivers: staging: wilc1000/host_interface.c Fix sparse warning: right shift by bigger than source value
  2017-06-25 14:40 [PATCH] drivers: staging: wilc1000/host_interface.c Fix sparse warning: right shift by bigger than source value Guillermo O. Freschi
  2017-06-26 10:27 ` kbuild test robot
  2017-06-26 11:29 ` [PATCH v2] " Guillermo O. Freschi
@ 2017-06-26 11:47 ` Guillermo O. Freschi
  2 siblings, 0 replies; 4+ messages in thread
From: Guillermo O. Freschi @ 2017-06-26 11:47 UTC (permalink / raw)
  To: Aditya Shankar, Ganesh Krishna, linux-wireless; +Cc: Guillermo O. Freschi

Shifting by equal to or bigger than the width of a type results in
undefined behavior. By using a wide enough temporary variable the issue
can be avoided.

Signed-off-by: Guillermo O. Freschi <kedrot@gmail.com>
---
 drivers/staging/wilc1000/host_interface.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/wilc1000/host_interface.c b/drivers/staging/wilc1000/host_interface.c
index f7c22d7b28d1..4591b1452df4 100644
--- a/drivers/staging/wilc1000/host_interface.c
+++ b/drivers/staging/wilc1000/host_interface.c
@@ -2407,6 +2407,7 @@ static void Handle_SetMulticastFilter(struct wilc_vif *vif,
 	s32 result = 0;
 	struct wid wid;
 	u8 *pu8CurrByte;
+	u32 enabled;
 
 	wid.id = (u16)WID_SETUP_MULTICAST_FILTER;
 	wid.type = WID_BIN;
@@ -2416,10 +2417,12 @@ static void Handle_SetMulticastFilter(struct wilc_vif *vif,
 		goto ERRORHANDLER;
 
 	pu8CurrByte = wid.val;
-	*pu8CurrByte++ = (strHostIfSetMulti->enabled & 0xFF);
-	*pu8CurrByte++ = ((strHostIfSetMulti->enabled >> 8) & 0xFF);
-	*pu8CurrByte++ = ((strHostIfSetMulti->enabled >> 16) & 0xFF);
-	*pu8CurrByte++ = ((strHostIfSetMulti->enabled >> 24) & 0xFF);
+
+	enabled = strHostIfSetMulti->enabled;
+	*pu8CurrByte++ = (enabled & 0xFF);
+	*pu8CurrByte++ = ((enabled >> 8) & 0xFF);
+	*pu8CurrByte++ = ((enabled >> 16) & 0xFF);
+	*pu8CurrByte++ = ((enabled >> 24) & 0xFF);
 
 	*pu8CurrByte++ = (strHostIfSetMulti->cnt & 0xFF);
 	*pu8CurrByte++ = ((strHostIfSetMulti->cnt >> 8) & 0xFF);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2017-06-26 11:47 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-06-25 14:40 [PATCH] drivers: staging: wilc1000/host_interface.c Fix sparse warning: right shift by bigger than source value Guillermo O. Freschi
2017-06-26 10:27 ` kbuild test robot
2017-06-26 11:29 ` [PATCH v2] " Guillermo O. Freschi
2017-06-26 11:47 ` Guillermo O. Freschi

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